Ratchet-type safety closure

ABSTRACT

The invention contemplates a safety closure cap and necked bottle having coacting features of threaded and ratchet-locking engagement. In a preferred form, the ratchet-locking element of the bottle includes two diametrically opposed radially outwardly cantilevered wing members each having an upwardly directed ratchet tooth and integrally formed with the bottle neck. Each ratchet tooth has ratchet engagement with ratchet-tooth formations within the skirt of the closure cap, and each wing member is axially downwardly deflected in the course of securing the cap to the bottle, so as to resiliently load the wing member into arcuately extensive stabilizing contact with the skirt for a fully engaged relation of the ratchet-engaged parts. By having the ratchet teeth on the wing members at other than an integer multiple of the basic periodicity of tooth formations on the cap, it is possible to offer more ratchet-lockable angular positions, per revolution of the cap, than there are tooth formations in the cap.

United States Patent [1 1 Landen [451 May 6,1975

[ RATCI'IET-TYPE SAFETY CLOSURE [76] Inventor: William James Landen, 30

Fairwood Dr., Cheshire, Conn. 06410 [22] Filed: July 2, I974 [21] Appl.No.: 485,104

3,700,133 10/1972 Bagguley 215/221 Primary Examiner-George T. HallAttorney, Agent, or Firm1-lopgood, Calimafde, Kalil, Blaustein &Lieberman [57] ABSTRACT The invention contemplates a safety closure capand necked bottle having coacting features of threaded andratchet-locking engagement. In a preferred form, the ratchet-lockingelement of the bottle includes two diametrically opposed radiallyoutwardly cantilevered wing members each having an upwardly directedratchet tooth and integrally formed with the bottle neck. Each ratchettooth has ratchet engagement with ratchet-tooth formations within theskirt of the closure cap, and each wing member is axially downwardlydeflected in the course of securing the cap to the bottle, so as toresiliently load the wing member into arcuately extensive stabilizingcontact with the skirt for a fully engaged relation of theratchet-engaged parts. By having the ratchet teeth on the wing membersat other than an integer multiple of the basic periodicity of toothformations on the cap, it is possible to offer more ratchet-lockableangular positions, per revolution of the cap, than there are toothformations in the cap.

10 Claims 8 Drawing Figures 1 RATCHET-TYPE SAFETY CLOSURE This inventionrelates to bottles or the like containers adapted to contain hazardoussubstances, and more particularly relates to safety closures for suchcontainers which render them child-resistant, i.e., resistant totampering by children.

It is an object of the invention to provide a new and improved neckconstruction for such a container, particularly to receive andratchet-lock a safety cap of the variety having rotary engagement to theneck, as by threads.

Another object of the invention is to provide a new and improved bottleconstruction integrally incorporating a safety lock feature withoutdetriment to manufac turing economy and readily lending itself toautomatic production-line facilities for filling and capping a bottle.

A further object of the invention is to provide a new and improvedsafety cap and bottle combination in which the cap is readily lockedonto the bottle but may be unlocked therefrom by a very simplemanipulation of a part of the bottle itself.

A still further object is to meet the above objects with a constructionof inherent low cost, involving minimum alteration of presentconstructions.

It is a specific object to provide the above-noted features inapplication to injection-blow-molding of plastic containers, andinvolving minimal change in container molds.

Another specific object is to meet the above objects with structurerequiring no additional parts but rather involving simple modificationof existing bottle and cap parts.

Other objects and various further features of novelty and invention willbe pointed out or will occur to those skilled in the art from a readingof the following specification in conjunction with the accompanyingdrawings. In said drawings, which show, for illustrative purposes only,a preferred form of the invention:

FIG. 1 is a perspective view of assembled and safetylocked cap andbottle parts of the invention;

FIG. 2 is a view in side elevation of neck formations of the bottle ofFIG. 1;

FIG. 3 is a plan view of neck formations of FIG. 2; FIG. 4 is a verticalsectional view of the cap of FIG.

FIG. 5 is a side-elevational view of the bottle-neck region, the aspectbeing normal to the parting line identified in FIG. 3;

FIGS. 6 and 7 are similar enlarged fragmentary sectional views toillustrate successive relations of cap positioning on the neck, for theparts of FIG. 1; and

FIG. 8 is a greatly enlarged fragmentary view, partly broken away and insection, along line 88 of FIG. 7, to illustrate a ratchet-toothengagement.

Referring to the drawings, the invention is shown in application to acontainer or bottle 10 having an integral threaded neck 11 andselectively opened and closed by a cap having a threaded bore 13. Thebottle may be of any plastic material suitable for injectionblow-moldedmanufacture, and high-density polyethylene is indicated as such amaterial. In such manufacture, the entire neck region 11 is defined byan injection-type two-part mold such that each half of the mold definesa generally semi-cylindrical half of the bottle, with symmetry about aparting line which includes the neck axis, as suggested by legend inFIG. 3. Cap 12 may be of any suitable construction, being typically aninjection-molded part, for the case of a plastic bottle 10.

In the preferred embodiment of the invention, the neck region of thebottle, at the base end of the threads, is integrally formed with tworatchet-wing members or tabs 14-15, at diametrically opposite locationsand in axially offset relation to the bulbous enlargement of theadjacent upper body part of the bottle. A single ratchet tooth 16 oneach of these members faces upwardly for ratchet engagement withdownwardly facing ratchettooth formations 17 distributedcircumferentially about the lower end of the bore of the cap; stated inother words, the formations'l7 characterize a counterbore within theskirt 18 by which the open end of the cap is smoothly and continuouslydefined. The outer end 19 of each wing member projects externally of theapplied cap and is preferably upwardly flanged in axially overlappingand radial-clearance relation with the adjacent skirt surface 18.

More specifically, each wing member or tab 14 (15) is generally flat,having a transverse section characterized by substantially greater widthW than thickness T and oriented so that the upper surface can havesmooth and relatively extensive stabilizing contact with the lower edgeof skirt 18, such contact being of course applicable for a fully-engagedratchet condition. Also, the upward projecting extent or height H of theratchet tooth 16 is preferably slightly less than the depth D of each ofthe tooth formations 17 of the cap, so that in the engaged condition(see FIG. 8), a clearance 20 exists while the flat upper surface 21 ofmember 14 is in full contact with skirt 18. Typically, the sectionalproportions are such that W is in the order of 5 times T, thus favoringessentially only axially compliant deflection of the cantilevered end ofeach tab, and the tab width W is several times the effective width W ofratchet tooth 14, for example in the order of 4 times the tooth width.Additionally, in the unstressed state, i.e., prior to cap contact witheither of the tabs (FIG. 6), the tabs 14-15 are upwardly inclined to anextent a above a radial plane through the neck region, and the junctureto the neck is selected to provide substantial takeup (reduction) of theangle a in the course of achieving a cap-closed condition of thecontainer (FIG. 7). Still further, the locking face 22 of tooth 16 iscentrally positioned with respect to the width dimension W and is alsocoincident with the parting line (see FIG. 3) so as to provide cleandefinition of the surface which must bear the brunt of any attemptedunthreading of the cap, for a ratchet-engaged condition.

In the operation of the device, cap placement and its threaded advanceon neck 11 drives the lower end into escaping ratchet engagement withteeth 16, the inclination angle a being reduced as compliant reactiondevelops in approach to the fully closed condition (FIG. 7). The cap islocked and cannot be unthreaded, in the absence of deliberate downwarddeflection of both finger flanges 19. Unauthorized attempted unthreading(i.e., while ratchet-engaged) is met with firmly stabilized resistanceby the locking-face engagement at 22, it being noted that the effectivecenter of such resistance is close to (i.e., is offset very little from)the tab surface 21 and that the adjacent lateral supporting extent(designated W/ 2 in FIG. 8) of surface 21 is several times the offset ofsaid effective center.

1f the number of ratchet-tooth formations 17 is even, and the teeth 16are in true diametrically opposed relation, then teeth 16 of both wingmembers 14-15 will operate in unison, to provide as manyratchet-lockable positions per cap revolution as there are toothformations 17. If on the other hand, the number of formations 17 is odd,then teeth 16 of wing members 14-15 will operate in interlacedalternation, providing twice as many ratchet-lockable positions per caprevolution as there are tooth formations 17. Stated in other words, sucha staggered interlace of ratchet actions enables a finer angularprecision with which a given closed condition of the container can beheld. The criterion for such interlace action is that the teeth 16 shallbe angularly spaced by an odd-integer multiple of one half the effectiveangular spacing of adjacent formations 17, while for teeth 16 ratchetingin unison such angular spacing is at an integer multiple of the spacingbetween adjacent formations 17.

In further illustration of the invention, 1 shall set forth pertinentillustrative dimensions for the case of a container having a neck withtwo turns of helical threads, radially raised from a cylindrical necksurface of 0.990- inch diameter, the threaded extent being 0.450 inchalong the outer end of the neck. The wing members 14-15 extend to amaximum unstressed span of 1.850 inch, measured across flanges 19. Teeth16 are 0.060- inch wide by 0.060-inch high and are supported by a tabsection 0.250-inch wide and 0.040-inch thick, being defined betweeninner radii of 0.670 and 0.730 inch. Cooperating with such is a cap 12of 1.550-inch diameter at skirt 19, and with 23 or 24 tooth formations17, depending upon whether interlaced or unison ratcheting is desired.

The described structure will be seen to have achieved all statedobjects. It represents the essence of parts simplicity and of number ofparts, and yet a fine degree of ratchet positioning is available withoutreducing the size of teeth 16 or formations 17. The ratchet-tabformations 14-15 are produced as relatively simple modification (forexample, by EDM-milling at the partingline region) of existinginjection-blow-molding mold halves.

While the invention has been described in detail for the preferred formshown, it will be understood that modifications may be made withoutdeparture from the claimed scope of the invention.

What is claimed is:

1. In combination, a bottle or the like having a body with an externallythreaded neck, and a safety cap with a body having a threaded bore toremovably engage said neck, the open end of said cap body having acounterbore comprising a circumferential succession of downwardlyexposed axially undulating ratchet-tooth formations within acircumferentially continuous skirt, and said neck being integrallyformed with two axially compliant radially outward ratchetwing membersat diametrically opposed locations beneath and adjacent the open end ofsaid cap body when the neck is closed by said cap, each wing memberextending radially outward of said skirt for manual access andcomprising a substantially flat element having a transverse section thatis substantially greater in width than in thickness, each wing memberbeing continuously formed with said neck in such orientation that thewidth dimension of the wing member extends over an arc about the neckaxis, whereby axially compliant flexure of the cantilevered outer end ofeach wing member is the favored mode of wing-member deflection, anupwardly projecting ratchet tooth integrally formed with the uppersurface of each wing member at the location of radial registry withratchet-tooth formations of said cap, the axial extent of upwardprojection of said ratchet teeth being less than the axial depth of saidratchet-tooth formations, whereby for each ratcheted engagement theassociated wing member is stabilized by relatively extensive continuousarcuate contact with said skirt, thus preventing bottoming contact ofthe ratchet tooth in any of the ratchet-tooth formations of said cap.

2. The combination of claim 1, in which each said ratchet tooth has aneffective width that is a relatively small fraction of the effectivewidth of its associated wing member.

3. The combination of claim 1, in which each said ratchet tooth iscentrally located with respect to the width dimension of its associatedwing member.

4. The combination of claim 1, in which each said ratchet tooth has asloping ramp face and an axially extending locking face, said ramp facebeing centrally located with respect to the width dimension of theassociated wing member.

5. The combination of claim 1, in which each wing member in itsunstressed state is cantilevered in an axially upward inclinedorientation and is so positioned that it is downwardly deflected inapproach to substantially a horizontal radial plane upon fully ratchetedcap closure of said neck.

6. The combination of claim 1, in which that part of each said wingmember which extends beyond said skirt includes an axially upward flangein axially overlapping and radially clearing relation with said skirt.

7. The combination of claim 2, in which said fraction is substantiallyone fourth.

8. The combination of claim 1, in which the proportion by which thewing-member width exceeds its thickness is in the order of 5:1.

9. The combination of claim 5, in which said unstressed inclination isin the order of 10 above a radial plane of said neck.

10. As an article of manufacture, a unitary integrally formedinjection-blow-molded plastic bottle having an injection moldedexternally threaded bottle-neck portion and a blow-molded bottle-bodyportion, said injection-molded bottle-neck portion integrally includinga ratchet wing member projecting radially outwardly from a locationaxially below the threaded region, said wing member being substantiallyflat and having a transverse section that is substantially greater inwidth than in thickness, the width dimension of said wing member beingso oriented as to extend over an are about the neck axis, wherebyaxially compliant flexure of the cantilevered outer end is the favoredmode of wing-member deflection, and an upwardly projecting ratchet toothintegrally formed with the upper surface of the wing member at alocation radially offset from said neck portion.

1. In combination, a bottle or the like having a body with an externallythreaded neck, and a safety cap with a body having a threaded bore toremovably engage said neck, the open end of said cap body having acounterbore comprising a circumferential succession of downwardlyexposed axially undulating ratchet-tooth formations within acircumferentially continuous skirt, and said neck being integrallyformed with two axially compliant radially outward ratchet wing membersat diametrically opposed locations beneath and adjacent the open end ofsaid cap body when the neck is closed by said cap, each wing memberextending radially outward of said skirt for manual access andcomprising a substantially flat element having a transverse section thatis substantially greater in width than in thickness, each wing memberbeing continuously formed with said neck in such orientation that thewidth dimension of the wing member extends over an arc about the neckaxis, whereby axially compliant flexure of the cantilevered outer end ofeach wing member is the favored mode of wing-member deflection, anupwardly projecting ratchet tooth integrally formed with the uppersurface of each wing member at the locatioN of radial registry withratchet-tooth formations of said cap, the axial extent of upwardprojection of said ratchet teeth being less than the axial depth of saidratchet-tooth formations, whereby for each ratcheted engagement theassociated wing member is stabilized by relatively extensive continuousarcuate contact with said skirt, thus preventing bottoming contact ofthe ratchet tooth in any of the ratchettooth formations of said cap. 2.The combination of claim 1, in which each said ratchet tooth has aneffective width that is a relatively small fraction of the effectivewidth of its associated wing member.
 3. The combination of claim 1, inwhich each said ratchet tooth is centrally located with respect to thewidth dimension of its associated wing member.
 4. The combination ofclaim 1, in which each said ratchet tooth has a sloping ramp face and anaxially extending locking face, said ramp face being centrally locatedwith respect to the width dimension of the associated wing member. 5.The combination of claim 1, in which each wing member in its unstressedstate is cantilevered in an axially upward inclined orientation and isso positioned that it is downwardly deflected in approach tosubstantially a horizontal radial plane upon fully ratcheted cap closureof said neck.
 6. The combination of claim 1, in which that part of eachsaid wing member which extends beyond said skirt includes an axiallyupward flange in axially overlapping and radially clearing relation withsaid skirt.
 7. The combination of claim 2, in which said fraction issubstantially one fourth.
 8. The combination of claim 1, in which theproportion by which the wing-member width exceeds its thickness is inthe order of 5:
 9. The combination of claim 5, in which said unstressedinclination is in the order of 10* above a radial plane of said neck.10. As an article of manufacture, a unitary integrally formedinjection-blow-molded plastic bottle having an injection moldedexternally threaded bottle-neck portion and a blow-molded bottle-bodyportion, said injection-molded bottle-neck portion integrally includinga ratchet wing member projecting radially outwardly from a locationaxially below the threaded region, said wing member being substantiallyflat and having a transverse section that is substantially greater inwidth than in thickness, the width dimension of said wing member beingso oriented as to extend over an arc about the neck axis, wherebyaxially compliant flexure of the cantilevered outer end is the favoredmode of wing-member deflection, and an upwardly projecting ratchet toothintegrally formed with the upper surface of the wing member at alocation radially offset from said neck portion.